It's not a pretty story, according to "Flacking for Big Pharma," an article by Harriet Washington in the American Scholar. Here's an excerpt:
[D]drugmakers sometimes agree to buy journal advertising only if it is accompanied by favorable editorial mentions of their products. Or their in-house stables of writers or hired pens generate “advertorials,” a Frankensteinian mix of medical content and marketing messages that can be indistinguishable from editorial material. “Pharmaceutical firms also inform journals,” Smith observes, “that they are receptive to buying huge volumes of reprints that favor their wares: The profits for the journal can easily reach $100,000.” Pharma’s journal ads tout not only products but also its hundreds of thousands of subsidized “educational opportunities.” Drug and medical-device makers spend $2 billion annually for more than 300,000 seminars and training opportunities, often held in the Bahamas or the Caribbean. The wolfed-on-the-run free pizza for harried medical residents that the industry has so sanctimoniously forsworn bears little resemblance to the sumptuous feasts, flowing wines, chartered flights, cruises, luxurious lodgings, golfing, snorkeling, and remarkably attractive sales reps that characterize these island educational junkets. “There’s a lot of bribery involved—the kids get pizza, the grownups get trips to Hawaii,” observed Marcia Angell, MD, professor of social medicine at the Harvard Medical School, former editor-in-chief of the New England Journal of Medicine (NEJM), and the author in 2004 of The Truth About the Drug Companies: How They Deceive Us and What to Do About It.